One season in a generation,
every 18.6 years, the moon rises as far north as it ever does before cycling
to the south again. In the fall of 2005 an observer standing on the Observatory
Mound of the Newark Earthworks will be able to gaze through the axis of
the Circle and Octagon to the exact point on the horizon of this northernmost
moonrise. While we do not know why the Indians 2000 years ago constructed
this amazing complex of earthworks, we do know that the axis connecting
the Circle and Octagon mounds will point our eyes to this once in a generation
What is the 2005 Moonrise?
during 2005 and 2006, the moon rises and sets at or near its northernmost
and southernmost extents along the eastern and western horizons. The
northernmost moonrise is an astronomical event that occurs only once
every 18.6 years and it is linked to a complicated cycle that was discovered
independently by several ancient cultures. The Newark Earthworks incorporate
alignments to the various moonrises and moonsets of the lunar cycle.
The main axis of the Octagon Earthworks, in particular, is aligned to
the northernmost rising of the moon.
What are the Newark Earthworks?
to archaeologist and author Chris Scarre, the Newark Earthworks are
one of the 70 wonders of the ancient world. Originally, the Newark Earthworks
were the largest series of mounds and earthen enclosures in the world.
It was built nearly 2,000-years-ago and included two giant circles,
one square, one octagonal, and one oval earthwork. The entire earthwork
complex covered nearly five square miles. It was part cathedral, part
cemetery, and part astronomical observatory.
When is the 2005 Moonrise?
rises at its northernmost point on the horizon once every
The next time the moon rises at its northernmost point on the horizon in its 18.6 year cycle is Thursday night, September 14, 2006, at 11:09 PM (Eastern Standard Time) or 12:09 AM (Daylight Savings Time).This day and time is not conducive to public viewing at the Octagon Earthworks. But on Saturday night,October 22, 2005, at 10:13 PM, the nearly full moon will rise very close to its northernmost point, providing a spectacular experience at the Octagon Earthworks at a time more conducive for a public observance.
detailed scientific discussion of this topic, please see
According to a reporter writing in The Columbus Dispatch, the moonrise alignment "remains only a theory" (Monday, April 18, 2005). Does this mean the moon might not rise along the axis of Octagon Earthworks in 2005 and 2006?
No. The alignment of the earthwork is a demonstrable fact of architecture that anyone can see and measure for themselves. The alignment of the northernmost moonrise at the latitude of Newark is a well understood fact of astronomy. There is no uncertainty about either of these facts.
The main axis of Octagon Earthworks is precisely aligned to the point on the horizon where the moon rises at its northernmost point. The moon will appear to rise along this alignment at 12:09 AM (Daylight Savings Time) on September 14, 2006, (and on a few other dates in 2005 and 2006 – please see F.A.Q. Focus).
Therefore, the reporter's statement is factually incorrect, but it also perpetuates confusion about the nature of scientific facts and theories. In science, a theory is not a guess or an unsubstantiated claim. A scientific theory is a logical explanation of a natural phenomenon based on systematic observations (scientific facts). Theories provide an explanatory framework for making sense of facts. In other words, theories do not become facts, they explain facts.
Perhaps the reporter meant to suggest that the claim that the ancient builders of the Octagon Earthworks intentionally aligned it to the northernmost rising of the moon was in question. Perhaps it is an accident that the Octagon is aligned to this significant astronomical event. This is a more interesting question. For a discussion of this issue please see, "Is it a coincidence?"
For more information about the nature of science see the following links:
The Skeptic's Dictionary: Science
Teaching about evolution and the nature of science
How do I get to Octagon Earthworks?
Please see the Directions pages
are not sure why the earthworks are aligned to the complicated lunar
cycle. It is much easier to show that an earthwork is aligned to an
astronomical event than it is to explain why it is that way. The earthworks
may have been used as astronomical observatories or the alignments may
have been a way of bringing the apparent movements of the moon down
to earth for ceremonial purposes. It is likely that a lunar calendar
was used to determine the timing of certain religious festivals, but
such a calendar would not have to be so big. The oral traditions of
contemporary American Indian tribes may provide a key to answering this
Octagon Earthworks are owned by the Ohio Historical Society and the
site is open to the public year-round during daylight hours.
What is the Hopewell culture? Is it an Indian tribe?
culture" is the name archaeologists have given to the people
who built the
of the Hopewell culture were farmers, fishers, hunters, and gatherers
of wild plant foods.